Merge branch 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...

[cascardo/linux.git] / fs / btrfs / volumes.c

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index bdc6256..da9e003 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2761,6 +2761,7 @@ int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
        u64 dev_extent_len = 0;
        u64 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
        int i, ret = 0;
+       struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
 
        /* Just in case */
        root = root->fs_info->chunk_root;
@@ -2787,12 +2788,19 @@ int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
        check_system_chunk(trans, extent_root, map->type);
        unlock_chunks(root->fs_info->chunk_root);
 
+       /*
+        * Take the device list mutex to prevent races with the final phase of
+        * a device replace operation that replaces the device object associated
+        * with map stripes (dev-replace.c:btrfs_dev_replace_finishing()).
+        */
+       mutex_lock(&fs_devices->device_list_mutex);
        for (i = 0; i < map->num_stripes; i++) {
                struct btrfs_device *device = map->stripes[i].dev;
                ret = btrfs_free_dev_extent(trans, device,
                                            map->stripes[i].physical,
                                            &dev_extent_len);
                if (ret) {
+                       mutex_unlock(&fs_devices->device_list_mutex);
                        btrfs_abort_transaction(trans, root, ret);
                        goto out;
                }
@@ -2811,11 +2819,14 @@ int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
                if (map->stripes[i].dev) {
                        ret = btrfs_update_device(trans, map->stripes[i].dev);
                        if (ret) {
+                               mutex_unlock(&fs_devices->device_list_mutex);
                                btrfs_abort_transaction(trans, root, ret);
                                goto out;
                        }
                }
        }
+       mutex_unlock(&fs_devices->device_list_mutex);
+
        ret = btrfs_free_chunk(trans, root, chunk_objectid, chunk_offset);
        if (ret) {
                btrfs_abort_transaction(trans, root, ret);
@@ -5762,20 +5773,17 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
                        }
                }
                if (found) {
-                       if (physical_of_found + map->stripe_len <=
-                           dev_replace->cursor_left) {
-                               struct btrfs_bio_stripe *tgtdev_stripe =
-                                       bbio->stripes + num_stripes;
+                       struct btrfs_bio_stripe *tgtdev_stripe =
+                               bbio->stripes + num_stripes;
 
-                               tgtdev_stripe->physical = physical_of_found;
-                               tgtdev_stripe->length =
-                                       bbio->stripes[index_srcdev].length;
-                               tgtdev_stripe->dev = dev_replace->tgtdev;
-                               bbio->tgtdev_map[index_srcdev] = num_stripes;
+                       tgtdev_stripe->physical = physical_of_found;
+                       tgtdev_stripe->length =
+                               bbio->stripes[index_srcdev].length;
+                       tgtdev_stripe->dev = dev_replace->tgtdev;
+                       bbio->tgtdev_map[index_srcdev] = num_stripes;
 
-                               tgtdev_indexes++;
-                               num_stripes++;
-                       }
+                       tgtdev_indexes++;
+                       num_stripes++;
                }
        }